A known type of lighting system, which is exemplified by the system disclosed in the aforesaid U.S. Pat. No. 4,811,722 - Davenport et al, comprises a bundle of optical fibers each having an input end, a light source, and a reflector for receiving light from the source and reflecting such light from the source into the input ends of the optical fibers for transmission by the fibers. It is desirable in such a system that light from the source be coupled into the optical fibers with the least possible loss of light. One factor that can result in undesired losses is the presence of voids between the optical fibers in the bundle. Any light from the source entering these voids represents lost light which is not transmitted by the optical fibers.